Adjustable fulcrum support for weighing scales



Aug. 23, 1932. I F. c. FISHER 1,372,920

- I ADJUSTABLB FULCRUN SUPPORT FOR WBIGHING SCALES Filed June 12. 19:51

ratenteu Aug. no, 190:-

v h ,2 v s" I H I spin-chi in use mi; 1i,

My invention has for its iebzect to provide a sugge ting means for the ac uated arts of weighing machines which also provides for variable adjustment of theperts to-niiiintaih 3*-themin"an accuriitebulence' relation relae t ivejto the rest of the operetingparts'." The invention provides a block havingv a. fulcrum supporting surface ,which is so supported that it may be ,adjusted and "yetflrnaintain ;5"'-the"rlationship of the surface to the fulchum point thereby enabling minute adjustdfthe other points and vertical? spetit to a; horizontal plane'andwit ture for such typeslof supporting means, the invention also makes provision for maintaining the contat't point of each su portingi 2& block constant with res ect-tethe istalices between the related fu'crum "points. This advantav prevents bindingor drawing of jthe Ynerh ers aud' inaccurate cooperetion with other parts of the machine during its opera when.

and udvanteges which will appear from the following description and upon examinati on ofvlthe drawing. Structures ontvtiriin the andfmey' bever'ied in their deteils'aiid sen the invention. To illustrate a 'p1"ec,-'

ticailui plication' of the' invention, I have i select a supporting member embodying the invention as an example of the various structures, and the details of such structures, 1 that containthe invention, and shall describe the selected structure hereinafter, it being understood that variations may be 4 made and that" certain features of my 'invenmay be used to advantage without a cor responding use of other features,*imd without departing from the spirit of the inventiom "The particular structure selected is ehewnin the accompanying drawing. 'Fig; 1 is e perspective view of the supportingsmemberr 1 Fig. 2 is a view ofloi'igitudinal section taken'through the member. .Fig. 3 isn sectional view of-the base of aweighing.

all. machine yghenein thexsupportingememben The invention consists in other, festures:

invention -may partake of different orms may be used. Fig. 4 is an inverted bottomview 'of thej'base of the machine and the operati'ng mechenism'l ocated therein. It =iswell=known that the actuated ele merits of a weighing machine are pivotal'l-y supported at four corners in the base of the" machine. The supporting members are usualljsuspended in the base by linksend when the members are not properly located relative'to each other, the actuated elements arethrown out ofbalance- To adjust the scale the links are then bent to varytheirfi length 'thus maintain the supporting members in their proper relation to the co actuating members; This method ofcorrecting errors hss been ioundjaulty sinoe'miniite' aid irstments'cennot be accurately determined? or made by the bending ofmetal: links to eitherfshorten orlengthen' them; 'The con-- tact point of thefulcrum on the surfedeof the-linkit moved with'respect to the 'othen fulcrum contmctoints upon changingfthe configuration ofhe link. This change of donfifiumtion is caused by the change in?- Iengt of the link andcannot be evoided and the-inclindtion of the surface that supports the fulcrum is also changed which alters the responsiveness' of the weighing me k nismi'w 1 j Inthe form of construction itlustratedin: the tirevrfngl have provided support mem= bets 1 vfor supportingthe actuating mambars of the weighing; machinei-"fflhesupport members are fonned'oftwo perts 2 and '3' that are-oounected" relative to each otherlby ai pnirof'bolts 4 that areloceted in theend's of the parts The parts ha ve 'semi circuler rextending transversely across "their surfaces, the groove 5 being formed in the bottom surface of the pert '2 and the 6 inthe upper or top surface of the part 3 The grooves 5 and 6 form a oentmlopen; ing 8 through the member 1 when the parts' 2 end- 3 are connected byfthe bolts 4. The part 2 may also be provided on its top surface with ;a, lugihalving a. central opening or eye-7 Dink-members 10 extend through the eyes?? oi the support members llnndthrough the slots-11 formed in-thebaae 19 of the machine osuspendthev' blocka Lthemimi; 2! 1.4;

In order to support the actuated elements by the members 1 within the base 12 of the machine, the actuated elements are provided with the pins 14 which may be formed as a E part of, or secured in, the ends of the actuated elements such as the parts 17 and 18. The parts 17 and 18 form the compound-lever 13 of the weighing mechanism. The pins 14' are rectangular in shape and the1r surfaces are inclined to the vertical so that when the pins are located in the supporting memat; parts of the weighing device; (not shown)- The lever part 17 is connected to the part 18 at a point which is substantially centrally located bet-ween the supporting members 1. The lever part 18 is semi-circular in form and the pins 15 ofthe supporting pins 14 are connected to the part 18 so as to extend into the openings 8 of the supporting members 1 which are located in the corners 20 of the rectangular opening 21 formed in the base of the machine. The part 18 is also provided with a pair of lugs 25 which are formed on the outer surface of the arm at a point that is midway between theends of the semicircular part of the arm and a rectangular pin 26 is secured in the lugs 25. The lever part 17 is formed in the shape of a Y and a pin 27 is located at the point of junction of the legs 28. The pins 16, which support the lever part 17, are located in the ends of the legs 28 and the members 1, supporting the lever part 17. are located in the corners 22 of the opening 21. The pins 26 and 27 are connected together by a metalloop or band 29. The lower corner of the pin 26 en gages the surface of the lower curve of the band 29 and the upper corner-of the pin 27 engages the surface of the upper curve of the band 29 to interconnect the lever parts 17 and 18. thereby forming the compound lever 13 and also providing for pivotal movement of the lever parts as they are moved angularly relative to each other.

The compound lever 13 is also provided with rectangular pins 30 which are located at equally spaced points between the pin 27 and the pins 16 on the lever part 17 and between pin.26 and pins 14 on the part 18. The pins 30 support saddle blocks 31 which are pivotally connected to the platform of the'weighing machine. The lower ends of the blocks 31 are provided with channels 32 which have semi-circular ends 33 so that, in the operation of the device, the engagement of the corners of the pins 30 on the surface of the ends 33 will allowfreemovement of the interconnected parts and also balance the platform.

The platform 38 is provided with four downwardly extending lugs 34. The lugs 34 are connected to the saddle blocks 31 which are provided at their upper ends with chonnels 35 The lugs extend into the channels and are pivotally connected to the blocks 31 by pins 36. Thus, the platform 38 is supported at one end on the lever part 17 and on the lever part 18 at the other. The lever parts, being pivotally supported at their outer ends and interconnected by the pins 26and, 27 and the band 29, will transmit equally any pressure exerted on the platform to the rest of the weighing machine.

Inorder to maintain the fulcrum points otthe, compound lever in a properly balanced relationship, the part 3 of the mem bars 1 may be raised or lowered relative to the part 2 by the rotation to bolts 4. How ever, since the part 3 of the member 1 18.

only moved vertically to adjust the location of the fulcrum point, the parallel relation bet-ween the pairs of pins 14 and 16, which support the compound lever 13, is not changed. Thus, any slight variation in the.

location of the fulcrum points may be made to provide correct operating of the weighing mechanism and assure pro r balance during continuous application 0 pressure.

I claim:

1. Ina weighing machine, the machine having a hollow base, a plurality of members, links connected to the base for supporting the members within the base, each of the said members being formed of two parts, the parts being connected by bolts and having semi-circular grooves formed in their adjacent edge surfaces, the said edges bein placed together to form transversely exten ing openings through the members, interconnected actuating members located in the base, the actuating elements having square pins located in their end portions, the pins extending into the openings of the. said first mentioned members to support the actuating, elements in the base of a machine and-means for moving the said parts of the said supporting members relative to each other to vary the location of the contact points of the pins of the actuated elements relative to each other.

2. In a weighing machine, the machine having a base, a plurality of members 10- in embers to change the locations of the points of ivotal contact of the said pins of the sai compound lever and for maintaining a constant relation between the wedge shaped pins and the semi-circular grooves.

3. In a Weighing machine, the machine having a hollow base, the plurality of members located Within the base, each of the mem bers being formed of two parts, the parts having semicircular grooves formed in their adjacent edge surfaces, the said edges forming openings when the parts of the members are placed together, links for supporting the members in the base of the machine, actuating elements located between the said members, the elements being interconnected to form a compound lever, pins located on the sides of the compound lever and extending into the openings formed in the members, the planes of the surfaces of the pins being located at an angle to the vertical, the lower corners of the pins engaging the lower surfaces of the openings formed in the supporting members, and means for adjusting the location of the fulcrum points of the said pins relative to each other.

In Witness whereof I have hereunto signed my name to this s iecification.

RANK 0. FISHER. 

